Science
in Reach

The sources behind the explanation.

91 research entries for the three pilot topics. For the key sources, we also explain what they show and what they leave unanswered.

Source sheets for individual videos

Each sheet lists every factual claim in one video with its evidence location, evidence level, review date, and limitation.

Sources for “Why Copper Slows a Falling Magnet”

91 sources shown.

W17

In vitro neurons learn and exhibit sentience when embodied in a simulated game-world

Kagan et al. 2022, Neuron, DishBrain, 10.1016/j.neuron.2022.09.001

Study or document
Neuronal cultures on a microelectrode array with closed-loop feedback to a simulation
Finding
The authors report improved performance measures within Pong sessions.
Evidence location
DishBrain system architecture and results on performance under feedback
Limitation
Measurement, interpretation as learning, and a claim about sentience are different levels. Criticism is included as N1.

Full text (introduction, figure legends, discussion at the relevant evidence locations) · DOI: 10.1016/j.neuron.2022.09.001 · Checked 14 October 2026

Related explanation: What can living cells do without the animal?

W14

A scalable pipeline for designing reconfigurable organisms

Kriegman et al. 2020, PNAS, Xenobots, 10.1073/pnas.1910837117

Study or document
Computer-assisted shape search and fabrication of selected structures from frog cells
Finding
Cell material and body shape jointly influence the movement of the constructed structures.
Evidence location
Sections on simulation and the construction of living designs
Limitation
Distinguish simulation from the actual experiment; no clinical application demonstrated.

Full main text and Methods; SI Appendix not archived · DOI: 10.1073/pnas.1910837117 · Checked 14 October 2026

Related explanation: What can living cells do without the animal?

W16

Motile Living Biobots Self‐Construct from Adult Human Somatic Progenitor Seed Cells

Gumuskaya et al. 2023/24, Advanced Science, Anthrobots, 10.1002/advs.202303575

Study or document
Laboratory experiments with human airway cell groups and a neuronal culture
Finding
Cilia enable movement; the paper also reports bridging an artificial gap under certain conditions.
Evidence location
Results on anthrobot movement and the neuronal scratch-assay setup
Limitation
No human wound was studied. Small experimental setups and specific culture conditions limit generalisation.

Full text (Introduction, Results, Methods, authors) · DOI: 10.1002/advs.202303575 · Checked 14 October 2026

Related explanation: What can living cells do without the animal?

B1

Three-dimensionally printed biological machines powered by skeletal muscle

Cvetkovic et al. 2014, PNAS, 10.1073/pnas.1401577111

Study or document
Experiment with cultured skeletal muscle tissue and a soft printed frame
Finding
Electrical stimulation can trigger contraction and directed movement of the construct.
Evidence location
Results on the asymmetric bio-bot and the electrical stimulation protocol
Limitation
Controlled laboratory environment; muscle-driven movement is not evidence of autonomous decision-making.

Full text (Abstract, Significance, Results, Methods) · DOI: 10.1073/pnas.1401577111 · Checked 14 October 2026

Related explanation: What can living cells do without the animal?

B2

Optogenetic skeletal muscle-powered adaptive biological machines

Raman et al. 2016, PNAS, 10.1073/pnas.1516139113

Study or document
Experiment with optogenetically controlled muscle tissue
Finding
Light pulses can trigger muscle contractions in the bio-bot.
Evidence location
Results on optical stimulation; construction of the light-sensitive muscle tissue
Limitation
Further development in the same research setting as B1; not an independent replication of a general capability.

Full text (Abstract, Results, Methods) · DOI: 10.1073/pnas.1516139113 · Checked 14 October 2026

Related explanation: What can living cells do without the animal?

N1

A response to claims of emergent intelligence and sentience in a dish

Balci et al. 2023, Neuron 111(5):604-605, 10.1016/j.neuron.2023.02.009 (HAL manuscript, submittedVersion)

Study or document
Scholarly commentary, not a new experimental study
Finding
The authors criticise the interpretation and terminology in the DishBrain paper and question the strength of some results.
Evidence location
HAL manuscript, paragraphs on sentience, intelligence, and generalising the findings
Limitation
The submittedVersion was read. This text alone does not represent the complete scientific exchange.

Scholarly commentary; HAL manuscript read (submittedVersion) · DOI: 10.1016/j.neuron.2023.02.009 · Checked 14 October 2026

Related explanation: What can living cells do without the animal?

gweon2026

Association Between Sugar-Sweetened and Artificially Sweetened Beverage Intake and Gastric Cancer Incidence

Gweon TG et al. (2026), Gastro Hep Advances

Study or document
Prospective observational analysis of two US cohorts; research letter
Finding
112,284 participants, 278 cases; highest sugar-sweetened beverage group versus never use (less than one serving a month): adjusted HR 2.45 (95% CI 1.49–4.04).
Evidence location
Results paragraph and table: multivariable-adjusted model, total cohort
Limitation
No proof of causation. The category boundary is worded differently in the text and table; information is limited on factors including H. pylori.

Prospective cohort (research letter) · DOI: 10.1016/j.gastha.2026.101097 · Checked 14 October 2026

Related explanation: Soft drinks and stomach cancer: what does 2.45 mean?

jayedi2026_cup

Sugar sweetened and artificially sweetened beverages, fruit and vegetable juices and cancer risk: a World Cancer Research Fund International Global Cancer Update Programme (CUP Global) systematic literature review and meta-analysis

Jayedi A et al. (2026), medRxiv (Preprint, not peer-reviewed)

Study or document
Preprint: systematic review and dose–response meta-analysis
Finding
Stomach cancer analysis with two cohorts; limited evidence without a firm conclusion.
Evidence location
Interactive evidence platform linked in the preprint (stomach cancer entry); preprint posted 1 July 2026
Limitation
Not peer-reviewed; as of 14 October 2026 no journal version is listed. A later published version may differ.

Systematic review and dose–response meta-analysis of cohorts (search to September 2024) · DOI: 10.64898/2026.06.22.26355879 · Checked 14 October 2026

Related explanation: Soft drinks and stomach cancer: what does 2.45 mean?

pan2023

Association of soft drinks and 100% fruit juice consumption with risk of cancer: a systematic review and dose–response meta-analysis of prospective cohort studies

Pan B et al. (2023), Int J Behav Nutr Phys Act

Study or document
Systematic review and dose–response meta-analysis of prospective cohorts
Finding
For stomach cancer per 250 mL/day: RR 1.00 (95% CI 0.85–1.17); certainty of evidence rated very low.
Evidence location
Stomach cancer results in the dose–response analysis and GRADE table
Limitation
Only two studies contribute to this estimate. No established null effect; the comparison is not identical to the highest group in the US study.

Systematic review and dose–response meta-analysis of prospective cohorts (to June 2022) · DOI: 10.1186/s12966-023-01459-5 · Checked 14 October 2026

Related explanation: Soft drinks and stomach cancer: what does 2.45 mean?

li2021

Consumption of sugar-sweetened beverages and fruit juice and human cancer: a systematic review and dose-response meta-analysis of observational studies

Li Y et al. (2021), Journal of Cancer

Study or document
Systematic review of observational studies with mixed study designs
Finding
Stomach cancer analysis: pooled RR 0.99 (95% CI 0.79–1.29), six studies.
Evidence location
Stomach cancer subgroup and analysis by study design
Limitation
Case-control and cohort studies differ; overlaps with other reviews prevent simply adding the evidence together.

Systematic review and meta-analysis, 71 observational studies (32 case-control, 39 cohort) · DOI: 10.7150/jca.51322 · Checked 14 October 2026

Related explanation: Soft drinks and stomach cancer: what does 2.45 mean?

hp-faq

HP Instant Ink: frequently asked questions (Germany)

HP, manufacturer documentation (Germany)

Study or document
Manufacturer documentation for Germany
Finding
HP describes subscription cartridges ceasing to function after the relevant billing period and points to regular cartridges.
Evidence location
Question about the consequences of cancelling Instant Ink
Limitation
Evidence for a manufacturer statement, not an independent product test. Details may change.

Manufacturer documentation; retrieved again on 11 October 2026 and relevant evidence locations read · Retrieved 11 October 2026

Related explanation: Why full HP Instant Ink cartridges stop printing after cancellation

hp-terms

HP Instant Ink: contract terms (Germany)

HP, manufacturer documentation (Germany)

Study or document
The provider’s contractual terms for Germany
Finding
The archived terms describe deactivation and continued printing with regular HP cartridges compatible with the printer.
Evidence location
Section 9: cancellation; version last updated November 2025, archived on 11 October 2026
Limitation
Terms as retrieved on 11 October 2026; HP may change them. No assessment of an individual contractual case.

Manufacturer documentation; retrieved again on 11 October 2026 and relevant evidence locations read · Retrieved 11 October 2026

Related explanation: Why full HP Instant Ink cartridges stop printing after cancellation

hp-plus

HP+: frequently asked questions (Germany)

HP, manufacturer documentation (Germany)

Study or document
Manufacturer FAQ on HP+
Finding
Separate requirements and conditions for the HP+ offering.
Evidence location
Question about requirements for HP+
Limitation
The FAQ covers HP+; it does not describe the Instant Ink terms.

Manufacturer documentation; retrieved again on 11 October 2026 and relevant evidence locations read · Retrieved 11 October 2026

Related explanation: Why full HP Instant Ink cartridges stop printing after cancellation

Each entry shows the date we last checked it. The register distinguishes existing research sources from the annotated key sources. It does not replace individual checks of usage rights for figures and videos.